package com.learning.util.netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import static io.netty.util.CharsetUtil.UTF_8;

@ChannelHandler.Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        super.channelRead(ctx, msg);
        ByteBuf buf = (ByteBuf) msg;
        System.out.println("Server received: " + buf.toString(UTF_8));
        //将接收到的消息写给发送者，而不冲刷出站消息
        ctx.write(buf);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        super.channelReadComplete(ctx);
        //将未决消息冲刷到远程节点，并且关闭该 Channel
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(
                ChannelFutureListener.CLOSE);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
        cause.printStackTrace();
        ctx.close();
    }
}
